Heads-up speed display for vehicles

ABSTRACT

A heads-up speed sensing display and control system for apprising an operator of the risk of operating a vehicle at various speeds has a risk indicator display with a plurality of illuminable elements, such as three different colored LEDs, illuminable in a plurality of patterns, each of the plurality of patterns having a predetermined correlation to vehicle speed, such as green for safe, yellow for caution and red for hazardous. A speed sensor, such as a Hall-effect device is coupled to a driven element of the vehicle, like a speedometer cable, and causes the speed sensor to generate a signal indicative of vehicle speed. A control unit receives the speed signal and selects an illumination pattern to indicate the risk of operation at the speed the vehicle is then traveling. The display may be wired or wireless and be attached to a windshield, face guard or helmet. The display system may be customizable to the operator and the environmental conditions and may be coordinated with a signage system using the same risk indicator conventions. The indicator system may also be used as a governor. In yet another embodiment, GPS data is used in a lookup table to ascertain the speed limit for the operation of the vehicle at any given time and place. The speed limit information is used to inform a governor which reduces vehicle speed to the ascertained limit. The ascertained speed limit may be used to select a risk indicator pattern for the actual operating speed of the device.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application Ser.No. 60/599,451 entitled, Heads-Up Speed Display For Vehicles, filed Aug.6, 2004.

FIELD OF THE INVENTION

The present invention relates to speed indicators for moving vehiclesand more particularly, to speed indicators provided proximate to adriver's forward looking line of sight.

BACKGROUND OF THE INVENTION

Various speed indicators have been proposed to effectively provide adriver of a vehicle with speed information. These known speed indicatorswould include various “heads-up” displays, the basic concept of which isto provide the speed indicator display at a position close to thedriver's line of sight as the driver looks forward towards the directionof travel, e.g., when the driver of an automobile is looking at the roadand traffic in front of a forward moving vehicle. Many of the heads-updisplays proposed are directed at applications on automobiles andairplanes.

The operation of snowmobiles, jet skis, ATV's (all terrain vehicles) andmotorcycles, in particular, trail bikes, present additional anddifferent conditions for monitoring speed than those presented byautomobiles and airplanes. Water and off-road conditions can be expectedto vary more rapidly and severely than the conditions of a paved road orthe open sky. For example, a fallen tree or boulder may impede thecourse of a trail bike. A snowmobile may encounter deep powder, ice or apatch of mud, depending upon the place where it is operated, the season,etc. Similarly, partially submerged tree limbs, barrels, rope, etc. mayconstitute an unexpected obstacle to a jet ski. As a result, it isimperative for operators of off-road vehicles to be highly vigilant forany obstructions or changes in the surface in the path of their vehicle.This vigilance makes it more desirable that the driver look forward atall times, rather than looking down at a speedometer. The degree ofsurface roughness encountered in off-road travel frequently makes itdifficult or impossible for the operator of a jet ski, snowmobile ortrail bike to read a speedometer due to the driver's and the vehicle'srelative movement. Because off-road vehicles like jet skis, trail bikesand snowmobiles typically do not have closed cabs, weather conditionssuch as rain, snow, icing, fogging, may also act to reduce or eliminatethe driver's capacity to visualize a speedometer. Since the environmentin which an off-road vehicle is operated may vary widely, and someenvironments provide a distorted and/or different perception of speed(e.g., travel over a frozen lake will provide a different sense of thespeed of a snowmobile than travel through the wood), operators ofoff-road vehicles can not rely solely on their innate perception ofspeed and should utilize an objective measure of speed, such as aspeedometer.

The factors of trail difficulty, driver expertise and weather conditionsall contribute to ascertaining the speed at which a particular trail maybe traveled in safety. If the operator of an off-road vehicle, such as asnowmobile, exceeds a safe speed range for the particular combination ofskill level, trail and weather conditions, accidents and injuries canresult. Accordingly, an effective system for apprising operators ofoff-road vehicles of speed related risk associated with operating theirvehicle while allowing them to focus on the landscape in front of themis highly desirable.

SUMMARY

The limitations of prior art speed indicators are addressed by thepresent invention, which includes a visual indicator for apprising anoperator of a vehicle of the level of risk associated with operating thevehicle at a given speed. The visual indicator includes a plurality ofilluminable elements illuminable in a plurality of patterns. Thepatterns have a predetermined correlation to safety of operation at agiven vehicle speed. The visual indicator receives a signal indicativeof vehicle speed and displays one of the plurality of illuminablepatterns in response to the signal. The visual indicator is positionableproximate to the operator's line of sight while the operator isoperating the vehicle and is visible to the operator when the operatoris looking at a spatial position towards which the vehicle is traveling.

In accordance with a method of the present invention, a plurality ofspeed limits associated with a plurality of geographic positions arestored in a computer-accessible memory. The geographic position of thevehicle is ascertained using a GPS receiver and the speed limit for thegeographic position of the vehicle stored in memory is accessed by acomputer by looking up the speed limit for the applicable geographicposition. The actual speed of the vehicle is sensed with a speed sensorand compared to the ascertained speed limit. If the actual speed of thevehicle exceeds the ascertained speed limit, then engine power output isreduced until the speed of the vehicle is less than or equal to theascertained speed limit.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is perspective view of the front portion of a snowmobile viewedfrom the operator's perspective looking out the front windshield onwhich is mounted a speed indicator in accordance with an embodiment ofthe present invention.

FIG. 2 is a perspective view of a speed indicator in accordance with anembodiment of the present invention.

FIG. 3 is a perspective view of a speed sensor in accordance with anembodiment of the present invention.

FIG. 4 is an exploded view of the speed sensor of FIG. 3.

FIG. 5 is a perspective view of an electronic control unit in accordancewith an embodiment of the present invention.

FIG. 6 is a schematic diagram of the circuit components of an exemplaryembodiment of the present invention.

FIG. 7 is a perspective view of an alternative embodiment of the presentinvention.

FIGS. 8 and 9 are schematic diagrams illustrating another exemplaryembodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a vehicle V, such as a snowmobile or an ATV as seen by anoperator thereof. i.e., looking forward, out the front windshield W. Thesnowmobile V has a tachometer T and a speedometer S. In the vehicle Vshown, the tachometer T has a dial indicator and the speedometer S has adigital (numeral) readout. The speedometer S may be utilized by theoperator to determine the speed of the vehicle V over the terrain onwhich it is operated. The position of the speedometer S requires theoperator to direct his sight down, away from the windshield W in orderto determine the speed of the vehicle. As noted above, clearvisualization of the speedometer S may also be impeded by movement andweather conditions. A speed indicator 12 in accordance with the presentinvention is attached to the edge E of the windshield W. Because thespeed indicator 12 is positioned on the windshield, it is not necessaryfor the operator to look down in order to see it. In contrast, theoperator may continue to look up and in a forward direction to maintaina view of the terrain and simultaneously view the speed indicator 12.The speed indicator 12 is an array of three illuminable/extinguishabledisplay elements 14, 16, 18, each preferably displaying a differentcolored light, e.g., green, yellow and red. The display elements 14, 16,18 are preferably LEDs (light emitting diodes), but could also beconventional incandescent lights with different colored bulbs and/orlenses. Alternatively, the lenses may bear words, numbers or symbols,such as, “CAUTION”, “DANGER”, “SLOW DOWN”, etc. The speed indicator 12may be attached to the windshield W in any of a number of conventionalmethods, such as by adhesives, clamps, threaded fasteners, etc.Alternatively, the speed indicator 12 can be integrally molded into thewindshield or into a trim piece for covering the edge E of thewindshield W. The illumination of the display elements 14, 16, 18 may beused as a means of communicating information to the operator concerningthe speed of the vehicle and, in addition, the degree of safety/riskassociated with operating the vehicle at a given speed. For example, sixdifferent speed ranges could be encoded and indicated by the indicator12 as follows: (a) no element (14, 16, 18) lit=0 to 30 MPH (miles perhour); (b) element 14 lit green color=30 to 40 MPH; (c) element 16 lityellow=40 to 50 MPH; (d) element 18 lit red 50 to 60 MPH; (e) elements14, 16, 18 lit green, yellow and red, respectively, simultaneously=60 to70 MPH; (f) elements 14, 16, 18 flashing green, yellow, red,respectively, simultaneously=over 70 MPH. In this example, theilluminable elements are displayed in readily comprehensible, intuitivepatterns of illuminated and non-illuminated (extinguished) elements. Thegiven color patterns have a familiar meaning to drivers in that theyanalogize to traffic light signals with similar meaning. Further, thelighting of additional elements generates a more intense optical signalwhich would be appropriate for sending a stronger alert. The flashing ofthe display elements 14, 16, 18 is analogous to the common use offlashing lights to warn of danger. Accordingly, the speed indicator 12functions to apprise the operator of a vehicle of a speed range but inaddition communicates a message to the operator concerning the degree ofsafety/risk of operating the vehicle at the driven speed. As describedfurther below, this safety/risk message may be adjusted based uponfactors other than speed alone, e.g., based upon operator skill oroperating conditions attributable to environmental factors, such asweather or trail usage density (congestion).

FIGS. 3 and 4 show a sensor assembly 20 that may be retrofitted to anexisting speedometer, more particularly, a cable driven speedometer forgenerating an electrical signal indicative of the instantaneous speed ofthe vehicle. Sensor assembly 20 has a housing 22 with a hollow 24, athreaded nipple 26 and a sensor socket 28. A bushing 30 inserts throughthe hollow 24 and into nipple 26 to receive and support a trigger unit32 in bore 34, such that the trigger unit 32 rotates freely in bore 34.The trigger unit 32 has a cable receiver 36 with an interior hollowhaving a shape approximating that of the end of the speedometer cable ofthe vehicle in which it is installed, typically, a speedometer cable end(not shown) has a square cross-sectional shape. The trigger unit 32 hasa rotor element 38 with a plurality of trigger teeth 38 a, 38 b, totrigger a pulse in a Hall effect sensor 40 inserted into sensor socket28. A cable simulator/shaft 42 mimics the shape of the end of thespeedometer cable of the vehicle in which the sensor assembly 20 isinstalled and is used to transfer the rotation of the speedometer cableto the speedometer when the sensor assembly 20 is installed on thevehicle. The trigger unit 32 is captured in the housing 22 by a cap unit44, one end of which is crimped, welded, glued, threadedly attached orotherwise affixed to the housing 22 and the other end of which has athreaded rotatable sleeve 46 that screws onto the speedometer of thevehicle. As a result, the present invention extracts speed informationfrom the existing speedometer cable without interrupting itsfunctionality relative to driving the stock speedometer. This allows thepresent invention to be easily retrofitted and removed from a vehiclewithout destroying or interfering with the vehicle's originalfunctionality. In lieu of the above described sensor unit 20, a Halleffect sensor of this type could be driven off the drive train of avehicle or any driven element, e.g., off the chain or driveshaft finaldrive of a motorcycle or driven by the tread of a snowmobile.Furthermore, the speed signal input may be extracted from thespeedometer signal of vehicles having electronic speedometers.

FIG. 5 shows a control unit 48 containing the electronic circuitryrequired to interpret the pulses from the sensor unit 20 and outputcommands to the display unit 12. For example, the control unit 48 may beused to count the pulses received over a given time period, therebydetermining the frequency of pulses from which the rotational speed ofthe sensor and the associated speed of the vehicle may be calculated andthe appropriate display element(s) 14, 16, 18 illuminated. In apreferred embodiment of the invention, the control unit is programmable,such that the speed ranges associated with specific display illuminationpatterns may be changed. For example, for novice riders, the speedranges corresponding to low (safe), medium (heightened vigilancerequired) and high (extra vigilance warranted), etc. would be lower thanthe corresponding speed ranges for experienced and expert riders. Thiscapacity to reset/program the control unit 48 may be implemented byconventional digital input devices, such as switches or keypads or byanalog devices, such as variable capacitors, rheostats, etc. Aphotosensor, e.g., photoresistor (See FIG. 6) may be employed to providean input to the control unit 48 to control the intensity of the display(illumination brightness) based upon the ambient lighting conditions,viz., the brighter the ambient light, the brighter the display needs tobe in order to be readily observable.

The control unit 48 may be provided with an output to an engine controlcomputer or to a throttle control solenoid on the carburetor or fuelinjector of the vehicle for controlling the speed of the vehicle andthereby acting as a governor. This feature would be especially usefulfor vehicles that are rented to persons of unknown expertise or that areused by children or those with limited expertise. Even those who areexpert operators may benefit from use of a governor feature of thepresent invention, in that they may not be familiar with the specifictrail that they are riding on.

FIG. 6 shows an exemplary circuit 11 having a programmable integratedcircuit (control unit) 48, for example, standard electrical componentnumber PIC16F627 which receives signal output 58 (at pin number 6)generated by the Hall effect sensor 40. A voltage regulator 50, e.g.,standard electrical component 78(L)05, +5 Volt, allows the circuit 11 tobe powered by any typical vehicle voltage system, for example, 6, 12 or24 volts (from 6 to 36 volts) and can be connected to the vehiclewiring, preferably in a fused line controlled by the ignition switch.The output of the voltage regulator 50, namely V_(cc), is used to powerthe Hall effect sensor 40 through a voltage drop provided by resistorR4. The voltage signal powering Hall effect sensor 40 is filtered bycapacitor C4 to smooth spikes in voltage. Capacitor C5 and C6 providesimilar filtering functions for the output signal present on pin 2 ofthe Hall effect sensor 40. A dip switch 52 provides four combinedvoltage states corresponding to logical states 00, 01, 10 and 11 at pins12 and 13. This can be utilized to encode the user's level of expertiseranging from novice to expert. For example, 00 may indicate expert withnovice being 11. The switch 52 would typically be marked with thesettings in a descriptive format or with a number coding. The integratedcircuit 48 is programmed to count the pulses of the output signal 58which are indicative of the revolutions of the speedometer cable andtherefore the speed of the vehicle. The programming logic compares thepulse count (indicating revolutions per minute and speed) topredetermined threshold levels to ascertain the present speed range toilluminate the appropriate diode D1, D2, D3 element(s) 14, 16 and 18,which indicate to the driver the speed range of the vehicle, asdescribed above. A photo resistor 54 modulates the voltage dropexperienced by the light emitting diodes 14, 16, 18. Namely, as thelight diminishes, the resistance increases such that the LED's aredimmed. Accordingly, the brighter the ambient lighting, for exampleduring midday, the brighter the LED's must be in order to be visible.Conversely, the lower the ambient light, the dimmer the LED's 14, 16, 18need to be so as not to “blind” or distract the driver with anunnecessarily bright light.

The programmable integrated circuit 48 has an output 56 at pin 18 forcontrolling a governor circuit. Preferably, the governor acts directlyupon the vehicle's ignition system to pulse the ignition on and off,thereby diminishing the number of power cycles when vehicle speed isexcessive. For example, for a novice user, the program may determinethat a speed in excess of 30 miles per hour should trigger the governorto begin pulsing the ignition at 31 miles per hour. This pulsation ofthe ignition reduces the number of power pulses executed by the engineof the vehicle and thereby reduces the speed to at or below 30 miles perhour. A spark control mechanism for controlling the speed of the vehicleis preferred over a mechanism controlling throttle position via asolenoid or other electromechanical control which regulates throttleposition, in that the throttle position utilized for maintaining a speedbelow the threshold over-speed, for example 30 miles per hour, will varydepending upon the specific power demands experienced by the vehicle.For example, in climbing a hill, the throttle will have a more advancedposition than for level travel. Accordingly, a governor acting onthrottle position will not regulate the speed of the vehicle aseffectively in varying power demand situations.

In accordance with another aspect of the present invention, a trailmarking system may be employed wherein signage or display lights areshown on the trail that correspond to “speed limits” or suggested safespeeds for riding on the trail at that particular time and in thespecific weather conditions then prevalent. These trail markers or signsmay express the “speed limit” in terms of the patterns utilized by thespeed indicator 12, e.g., a green trail marker light could be used toindicate that operators should not exceed the speed range associatedwith the illumination pattern of a green display element 14 on theirspeed indicator. Note that a green trail marker light may result in adifferent “speed limit” in accordance with the present invention due todifferences in operator expertise or weather conditions.

In yet another embodiment of the present invention, the control unit maybe programmed to illuminate the display 12 based upon the geographicposition of the vehicle as determined by a global positioning device.This implies that the present invention includes or communicates with aglobal positioning device/receiver which can provide this geographicinformation and has a memory for storing the data associated with allpertinent geographic locations, e.g., in a lookup table. In this manner,the “speed limits” associated with specific portions of a trail orlandscape can be interactively and instantaneously determined based uponwhere on the trail or landscape the vehicle is located. As noted above,the present invention may be utilized as a governor by providing anoutput signal corresponding to the “speed limit” to an engine managementcomputer or to the controls associated with conventional governordevices, such as a cruise control system.

In accordance with yet another embodiment of the present invention, thedisplay 12 may be remotely controlled by the controller 48 by means of awireless connection. In that case, on-board power, such as a battery, isrequired for powering the speed indicator 12. In this manner, a wirelessspeed indicator 12 may be affixed to a windshield without the necessityof wires running from the unit which may adversely obscure the viewthrough the windshield, present a potential entanglement hazard and/oran unsightly appearance. Alternatively, a wireless display unit 12 couldbe affixed to the inside or outside of the face shield of a helmet orsomewhere else on the helmet within the ready viewing field of the userof the vehicle.

FIG. 7. shows a speed indicator 112 in accordance with anotherembodiment of the present invention. The speed indicator 112 has anarray of three display elements 114, 116 and 118, each preferablydisplaying a different colored light, such as LEDs or incandescentlights with colored lenses. The speed indicator 112 may be attached toan edge of vehicle body, windshield or helmet visor (windscreen) byclips 160 a, 160 b. As noted above, speed indicator 112 may be connectedto a control unit, such as control unit 48 shown in FIGS. 5 and 6, withthe control unit 48 illuminating the display elements 114, 116, 118 inaccordance with a predetermined convention for conveying the degree ofsafety of operation in various speed ranges, potentially as affected byoperator skill setting or environmental factors impacting safety ofoperation of the vehicle. The speed indicator 112 illustrates atamper-resistant interface for entering data pertaining to externalfactors, such as operator skill level, weather, etc., viz, via a switch162 actuable through access hole 164. When a slender pin such as a paperclip wire or needle is inserted through access hole 164 and the switch162 momentarily depressed, one of several levels of added risk factors(on a scale of 0 through 9) corresponding cumulatively to the increasein risk owing to driver inexperience, adverse weather conditions, trailcongestion, etc. may be selected. A numerical display 166 has aplurality of illuminable numbers (0-9) that indicate which level ofadded risk factor(s) has been chosen. The level of added risk factorchosen is communicated to control unit 48 which uses it to select thedisplay element(s) 114, 116, 118 to illuminate for a given speed. Forexample, if an expert rider and perfect environmental conditionscorrespond to an added risk factor of 0, then the speed range of 0 to 20m.p.h. could result in a green element 114 being displayed. If icyconditions exist, the added risk factor might rise to level 3 resultingin a green element 114 being illuminated in a speed range of 0 to 5m.p.h., a yellow element 116 being illuminated in the range of 6 to 8m.p.h., and a red element 118 being illuminated in the range of 19 to 25m.p.h.

FIGS. 8 and 9 show an alternative circuit for implementing the inventionwhere the reference numbers for like elements shown in FIG. 6 areincremented by 200.

It should be understood that the embodiments described herein are merelyexemplary and that a person skilled in the art may make many variationsand modifications without departing from the spirit and scope of theinvention. For example, the present invention has been described abovein reference to small, personal vehicles, such as snowmobiles and jetskis. It could also be used on boats, trucks and military vehicles.Further, while a visual output signal has been described, the presentsystem could readily incorporate an audio signal, e.g., with differentfrequency ranges indicative of speed and/or prerecorded digital messagesbeing announced, e.g., “Please reduce your speed—you are traveling inexcess of 50 miles per hour.” All such variations and modifications areintended to be included within the scope of the present invention.

1. A visual indicator for apprising an operator of a vehicle of thelevel of risk associated with operating the vehicle at a plurality ofdifferent speeds, comprising: a plurality of illuminable elementsilluminable in a plurality of patterns, said patterns having apredetermined correlation to safety of operation at a given vehiclespeed, said visual indicator receiving a signal indicative of vehiclespeed and displaying one of said plurality of illuminable patterns inresponse to the signal, said visual indicator positionable proximate tothe operator's line of sight while the operator is operating the vehicleand being visible to the operator when the operator is looking at aspatial position towards which the vehicle is traveling.
 2. The visualindicator of claim 1, wherein said visual indicator includes a speedsensor coupled to a driven element of the vehicle, said speed sensorsensing upon the motion of said driven element and generating saidsignal indicative of vehicle speed.
 3. The visual indicator of claim 2,wherein said visual indicator includes a control circuit that receivessaid signal indicative of vehicle speed, selects an illumination patternfrom said plurality of illumination patterns based upon said signalindicative of vehicle speed and outputs an illumination signal forilluminating said plurality of illuminable elements in one of saidplurality of illuminable patterns to indicate the degree of safety ofoperation of the vehicle at the present speed.
 4. The visual indicatorof claim 3, wherein said control circuit is programmable to variablyassociate selected speed ranges of the vehicle with ones of saidplurality of patterns indicating safety of operation based upon at leastone of operator expertise and environmental conditions.
 5. The visualindicator of claim 4, wherein said control circuit has an output actingas a governor controlling power output of an engine driving the vehicleto control the speed of the vehicle, such that the operator does notexceed a predetermined level of risk.
 6. The visual indicator of claim5, wherein said control circuit output for controlling power outputaffects the sparking rate of an internal combustion engine.
 7. Thevisual indicator of claim 5, wherein the control circuit is programmableto select a particular speed limit for the vehicle based upon at leastone of operator expertise and environmental conditions.
 8. The visualindicator of claim 2, wherein said driven element is a speedometer cableon the vehicle.
 9. The visual indicator of claim 2, wherein said speedsensor is a Hall effect device and said output signal indicative ofspeed is a plurality of pulses generated by the Hall effect device overa selected sampling period.
 10. The visual indicator of claim 9, whereinsaid visual indicator is retrofittable to an existing vehicle, saidspeed sensor inserting between an end of a stock vehicle speedometercable and an input of a stock speedometer and having a shaft forconducting the motion of the speedometer cable to the stock speedometerto preserve the operation of the speedometer.
 11. The visual indicatorof claim 1, wherein each of said plurality of illuminable elements havea color, at least two of said plurality are different colors and saidplurality of patterns includes pattern with at least one illuminableelement not illuminated.
 12. The visual indicator of claim 11, whereinsaid illuminable elements are light emitting diodes (LEDs).
 13. Thevisual indicator of claim 1, wherein said visual indicator is attachableto a windscreen.
 14. The visual indicator of claim 1, further includinga photoreactive circuit element for controlling the brightness of saidilluminable elements depending upon ambient lighting conditions, thebrightness being less for dimly lit ambient conditions and brighter forbright ambient conditions.
 15. A speed sensing display and controlsystem for apprising an operator of the risk of operating a vehicle atvarious speeds, comprising: a risk indicator display with a plurality ofilluminable elements illuminable in a plurality of patterns, each ofsaid plurality of patterns having a predetermined correlation to vehiclespeed; a speed sensor coupled to a driven element of the vehicle, saidspeed sensor sensing upon the motion of said driven element andgenerating a signal indicative of vehicle speed; and a control unit thatreceives said signal indicative of vehicle speed, selects anillumination pattern from said plurality of illumination patterns basedupon said signal indicative of vehicle speed and outputs an illuminationsignal for illuminating said plurality of illuminable elements in one ofsaid plurality of illuminable patterns to indicate risk of operation atthe speed then applicable to the operator, said risk indicator displaypositionable proximate to the operator's line of sight while theoperator is operating the vehicle and being visible to the operator whenthe operator is looking at a spatial position towards which the vehicleis traveling.
 16. The system of claim 15, wherein said plurality ofpatterns are implemented by at least one of extinguishing an element ofone color and illuminating an element of another color to indicate achange in risk associated with a change in speed, successivelyilluminating additional elements to indicate a change in risk, andflashing at least one element to indicate that the vehicle has attaineda particular level of risk associated with operation of the vehicle at agiven speed.
 17. The system of claim 16, further including a pluralityof signs posted in the environment through which the vehicle travels,each of said plurality of signs having a speed risk advisory visiblethereon to apprise an operator of a vehicle as to an appropriate risklevel for the vehicle in the vicinity of the sign, said sign expressingthe speed risk advisory in terms of one of said illumination patterns toallow comparison between the pattern shown on the sign and the patterndisplayed on said risk indicator display.
 18. The system of claim 15,wherein said control unit is programmable to allow inputting a selectedskill level for the operator, said control unit assigning saidillumination patterns indicating risk of operation at given speed rangesbased upon the skill level input.
 19. A method for controlling the speeda vehicle, comprising: storing a plurality of speed limits associatedwith a plurality of geographic positions in a computer-accessiblememory; ascertaining the geographic position of the vehicle using a GPSreceiver; accessing the speed limit for the geographic position of thevehicle with a computer by looking up the speed limit for the applicablegeographic position in the memory; sensing the speed of a vehicle with aspeed sensor; comparing the actual speed of the vehicle to theascertained speed limit; if the actual speed of the vehicle exceeds theascertained speed limit, then reducing engine power output until thespeed of the vehicle is less than or equal to the ascertained speedlimit.
 20. The method of claim 20, wherein the speed limits for each ofthe plurality of geographic positions include values associated with atleast one of operator expertise and environmental factors and furtherincluding the step of entering data into the computer pertaining to atleast one of operator expertise and environmental factors before saidstep of ascertaining, the computer finding the applicable speed limitbased upon geographic position and at least one of operator expertiseand environmental conditions during said step of ascertaining.
 21. Thevisual indicator of claim 1, wherein the signal indicative of vehiclespeed is a stock electronic input to a stock electronic speedometer.